Grain should not be stored in granaries or elevators if it is too wet or of poor quality due to excessive dryness. The current state of the art permits only a cursory and sometimes theoretical determination of this parameter, particularly during the busy harvest season. Presently used methods are also time consuming, and the devices are normally not portable.
It is a well known physical phenomenon that the ability to store energy or capacitance of an electrical circuit is directly proportional to the dielectric constant of the material between two conductors. It is also a well known electrical phenomenon that the frequency of an oscillating circuit is determined in part by the capacitance thereof. Therefore, it is quite common to measure the dielectric constant of a material by determining the frequency of oscillation of a circuit when the unknown dielectric is placed between two plates of a capacitor.
The quality of grain and/or its readiness for harvest may be determined in part by its dielectric constant. Current techniques require a rather cumbersome procedure for the measurement of grain quality; therefore, the lay elevator operator and farmer quite often neglect this measurement or obtain inaccurate results.